The effect of range of motion simulated with a patient-specific three-dimensional simulation analysis on dislocation after total hip arthroplasty

Background: Dislocation continues to be a common complication following total hip arthroplasty (THA). Although previous studies of computed simulation analysis investigated the range of motion (ROM), it is unclear whether the ROM before impingement simulated using computed tomography-based 3-dimensional simulation analysis (simulated ROM) is related to dislocation after THA. It is also unclear what angles are required in computed simulation analyses for stable hips after THA. In this study, we compared the simulated ROM in patients with and without dislocation. Methods: 16 patients with posterior dislocation were compared with 48 matched patients without dislocation. Risk factors including preoperative bone morphology of the hip, implant position, change of femoral offset, change of leg length, anterior aspect of the greater trochanter (GTa) length, and anterior inferior iliac spine length were also compared. Results: The mean flexion angle, internal-rotation at 90° flexion (IR) angle, cup anteversion based on the anterior pelvic plane (APP), tilt-adjusted cup anteversion and GTa length were significantly different between patients with dislocation and patients without dislocation ( p = 0.033, 0.002, 0.010, 0.047, 0.046). A receiver-operating characteristic curve analysis suggested cutoff points for flexion angle, IR angle, cup anteversion based on the APP, tilt-adjusted cup anteversion and GTa length, of 114.5°, 45.5°, 19.5°, 12.0° and 15.3 mm. Conclusions: This study suggests that preoperative planning to achieve a larger simulated ROM, flexion angle and IR angle, may reduce the risk of posterior dislocation. This study also suggests that fine-tuning of cup anteversion and/or trimming of the overhanging GTa during preoperative planning may reduce the risk of posterior dislocation.

C2–C3 Anterior Cervical Discectomy and Fusion (ACDF) for Hangman's Fractures with C2 Posterior Dislocation: A Modified Classification of Hangman's Fractures and Technical Notes

Background: The overwhelming majority of hangman’s fractures cause anterior dislocation of C2. Hangman’s fracture with C2 posterior dislocation is extremely rare, only one paediatric case was reported in 2018 to date. This kind of injury cannot be catalogued using current classification schemes and no established treatment recommendations exist. The purpose of this article is to report a rare case of a hangman's fracture with C2 posterior dislocation, which does not fit into existing classification systems, propose a new subtype of hangman’s fractures, and discuss management technical notes for the new subtype to avoid pitfalls. Methods: Description of case, review of relevant literatures and share our experience.Results: A 31-year-old male sustained hangman’s fracture with C2 posterior dislocation after fell into a 50cm deep roadside ditch when riding a motorcycle. Radiograph and computed tomography (CT) on admission showed fractures through both pars of C2 and C2 posterior dislocation. Magnetic resonance imaging (MRI) on admission showed high T2-weighted signal intensity of cervical spinal cord and compression of cervical spinal cord by posterior dislocation of C2 vertebral body. After 5 days of skull traction with 5 kg weight before operation, the dislocation aggravated. A C2-3 anterior cervical discectomy and fusion (ACDF) was performed. At 6 months after operation, bony fusion was achieved, and MRI showed the T2-weighted signal hyperintensity of cervical spinal cord before surgery disappeared.Conclusion: We proposed a new subtype of hangman's fractures here, type IIb hangman’s fractures: type II hangman’s fracture with C2 posterior dislocation. C2–C3 ACDF is recommended for type IIb hangman’s fractures. Traction before surgery is not recommended.

Closed posterior dislocation of ankle joint without fracture: A case report and literature review

Pure Ankle dislocation is an ankle dislocation without any associated fractures of the ankle and an intact tibiofibular syndesmosis. Only a few isolated case reports and small series of cases are reported in literature. We report a posterior dislocation of ankle joint without any bony fractures with description of its mechanism, management, and literature review Keywords: Pure Ankle dislocation; ankle dislocation without fracture; posterior dislocation of ankle.

Modified Mclaughlin procedure for neglected posterior dislocation of shoulder: short-term results

<p>Between 2017 to 2020, A prospective case series for assessment of short-term outcomes was carried out on 10 shoulders with 3 being bilateral cases and diagnosed as neglected posterior dislocation of shoulder at a tertiary care centre and treated with the Modified Mclaughlin procedure. All patients had articular defect ranging from 27-46% as confirmed with computerised tomography. All the surgeries were carried out by a single team of surgeons. After 24 weeks follow up of 10 shoulders with mean age 32 years, all patients were found to have excellent results in terms of ROWE and constant score. Patients had significant reduction in VAS score. Timely diagnosis of articular involvement plays a vital role in management for which computed tomography has a pivotal role. Depending upon the articular involvement, line of management is to be decided. So, it can be concluded that, in cases of articular defect &gt;25% following posterior dislocation of shoulder, better outcomes can be achieved with modified Mclaughlin procedure in terms of radiographic union and clinical scoring.</p>